In recent years, there has been substantial advancements made in speeding up the process of forming packages, such as pillow-type packages on a form, fill and seal packaging machine. The advancement is primarily in computerized combination weighing wherein addition to speeding up the overall packaging process. A leading approach in computerized weighing is set forth in the circuit described and claimed in U.S. Pat. Nos. 4,418,771 entitled "Method and Apparatus for Combination Weighing" and 4,538,692, entitled "Method and Apparatus for Combination Weighing With Multiple Storage Cups for Each Scale Hopper" owned by the present assignee.
Furthermore, substantial progress has been made in controlling the apparatus for actually forming the bag with advanced computer control. In the latest advancement, a computer control system is provided wherein a central processing unit (CPU), such as an IBM Compatible Computer with an Intel 486 microprocessor, including at least a 4-axis coordinator operates the package forming apparatus in a very efficient manner. Specifically, the combination weigher, the film feeder/seamer, the vibrating clamp for settling the product, and the moving carriage/stripper/sealing jaws are all synchronized so that maximum operating speeds in excess of 140 bags/minute, and even approaching 200 bags/minute, are attainable. This advanced system is described and claimed in copending applications assigned to the present application, including U.S. patent application Ser. No. 08/350,877 entitled "Continuous Vertical Form, Fill and Seal Packaging Machine With Synchronized Product Clamp", filed Dec. 7, 1994 now U.S. Pat. No. 5,040,035.
In terms of increased speed and overall operational accuracy, the advancement in the '877 application is proven to be very successful. The timing and interaction of the various components of the package forming apparatus and weigher is such so as to allow several product charges to be in transition from the weigher to the package forming apparatus at one time. This action is effective to eliminate dead time where one component waits on another, to thereby allow increased speed of operation. The various components for feeding/vertically seaming the film, clamping the film and settling the product and forming the transverse seal carry out the process in an optimum manner. No longer is the packaging machine set up in such a manner as to match the worst case scenario of these various components. For a complete and full description and understanding of this area of the overall packaging system, reference should be made to the '877 application.
Thus, the packaging machinery industry, and particularly with regard to form, fill and seal packaging machines, finds itself in a situation where computerized combination weighing is at a very advanced level to provide highly accurate weighing at greatly increased speeds, and the actual package forming apparatus and method has likewise reached a very advanced state. However, little or no control is provided in the area of transitional product flow between the weigher and the packaging forming apparatus. In other words, once the product charge from the combination weigher is formed until it reaches the package forming station, that is where the package is filled, formed and sealed, little or no advancement has been made. Essentially, the industry is still relying on the worst case scenario that occurs in the transitional product flow path along which the product charge must travel between the combination weigher and the package forming station. This results in the packaging machinery operator having to slow the system to accept the slowest product charge and the longest charge stringout (vertical spread), when in fact the machine/process is optimized in the other two areas (combination weighing/package forming). We have recognized that this transitional area of the packaging machine has become the proverbial bottle neck of the machine/system and we believe the time has come for its elimination.
Thus, an important aspect of the present invention is that the transitional flow path of a free flowing product, such as potato chips or other snack foods, is now recognized by us as being very important to the overall maximizing of the speed and efficiency of the packaging system.